Windows not working after flat battery

[chrism8168]

I have a 2001 996 C4 Cab . I let the battery go flat after the car had been standing for a few weeks. I had installed a new battery only a few weeks beforehand. I knew there was a fair chance it would go flat so had left the bonnet latch open so could get to the battery to jump start it and managed to get it going ok. However when I powered the drivers side window down , I couldn't get it up again. I took the car for a 30 minute drive but it would not reset the drivers window. I put the car on charge to let the battery upto to full charge. I had the hard top on and seemed to recall that I'd had windows out of synch previously and operating the hood a couple of times got them working again. So a couple of days later i removed the hard top and operated the hood. First time the passenger window went down and and came back up again when the hood came back up, but the driver window didn't move (still fully down) . I did it again but this time when the hood came up the pass window stayed down . I operated it a few more times but neither windows are now coming up . Any ideas appreciated.

 

[Geoff_Fields]

Possibly low battery voltage has confused the control module. Remove fuse that supplies windows, wait a few seconds and replace. Windows limits will need resetting, Motor each window to fully down by continuously pressing switch and hold for further 10 seconds, then motor up again by continuously pressing switch and hold for further 10 seconds.
Hope this helps with fixing your problem.

 

[chrism8168]

Thx for the suggestion but unfortunately that didn't work . This might be because the windows are are already powered down .

 

[andywill]

Hi Chris
Your symptoms do seem rather odd, re the driver’s side window the best option is to see if power is being supplied to the motor, apart from that if you could get the car plugged in to a proper Porsche tester that should save you time trouble and guesswork. Hopefully is just a doggy micro-switch of which there are a number, the tester should hopefully identify the culprit.
Good luck
Andy

 

[chrism8168]

Thx Andy. Will get into a specialist as soon as I can

 

[JHMotorsport]

Hi Chris,
Not sure where you are located but if you make it down to Hertfordshire M25 area then I can offer the use of my Durametric software to help your cause.
J

 

[jcollins]

Did this every get resolved? I've had the same issue but the passenger window went down when I jumped the car with a flat batter. Now (even with a new battery), it won't come back up.